Development of wear resistant pressing moulds for the production of diamond composites

In the powder metallurgical process, diamond material composites are produced by pressing and sintering of a mixture, consisting of diamond and metal powder like cobalt. Due to the high hardness of diamond, the surface of press die is easily damaged. To increase the life time of press dies, thin layers, deposited by PVD, has been employed. First, the standard tests, such as scratch test and pin-on-disc, were performed in order to characterize the adhesion and the tribology of the coatings. The results of standard tests were evaluated by 3D surface analyzer, SEM, and light microscope. Afterwards, PVD thin layers were deposited on the inner surface of the dies in order to analyze and compare their behavior during the compaction process. The results evidenced remarkable effect of thin PVD coatings on enhancing wear resistance of the press dies.